[1] To increase cruising speed and, in particular to provide reliability for night flying, the new design had three engines.

The two extra engines of the 350 were mounted at the ends of stub wings, more streamlined support structures than lifting surfaces, which extended horizontally from the lower fuselage longerons.

The outer engines were mounted as close together as possible, to minimize the couple resulting from the loss of power of one of them.

[1] They were housed in long, well streamlined cowlings that reached back as far as the wing trailing edge.

[1] The wings had constant chord with roughly elliptical tips, with roots joining the upper longerons.

[1] Each wing carried a pair of ailerons with trim tabs to reduce control loads.

Each unit had an axle, articulated at the lower longeron, and a pair of oleo legs fixed to the stub wing where the lift struts joined.